Cooling system for internalcombustion engines



A an-H021, 1953 E. c. KIEKHAEFER COOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES 2 Sl-lEETS-SHEET 1 Filed Oct. 26, 1949 IN V EN TOR.

April 19-53v E. c. KIEKHAEFER 2,635,591

COOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES Filed on. 26, 1949 Patented Apr. 21, 1953- COOLING SYSTEM F'oR INTERNAL- I COMBUSTIQN ENGINES- Elmer ClKiekhaefer, Cedarburg; intimation October 26, 1949,.Serial N0. 123L566 "This invention relates to" internal-combustion enginesand particularly'to water cooling systems therefor.

- The invention provides a plurality of coolant chambers which are disposed to receive coolant under pressure from a pump operated by the engine to cool specific portions of the engine. The chambers are connected in series and provided with discharge openings whereby certain of the chambers individually receive coolant for circulation according to the pressure of the coolant supplyand the speed and cooling requirements of the engine. I v

An object of the invention is to regulate the cooling of different parts of the engine according to the operating requirements of the engine.

Another object is to eliminate thermostatic devices ordinarily required to regulate the engine cooling.

Another object is to cool specific portions of the engine at predetermined relative temperatures.

A more particular object is to provide maximumcooling of, parts of a two-cycle engine ad-. jacent the exhaust ports and controlled cooling of other parts of the engine.

These and other objects and advantageswill be more fully set forth in the following description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

'In the drawings: j

Figure 1 is a side elevation of a two-cycle engine for an outboard motor having a vertically 9 c aims. (01. 123411.291

disposed crankshaft and with parts thereof broken away and sectioned to show twoof the coolant chambers of the engine;

Fig. 2 is an enlarged transverse'sectio'n taken on line 2-2 of Figure 1;

Fig. 3 is a side elevation of the opposite side of the engine with parts broken away to show the third coolant cavity;

Fig. 4 is a vertical transverse section through the engine adapted to show the several. coolant chambers and passages;

Fig. 5 is a diagrammatic illustration of the cooling circulation at low speeds; and

Fig. 6 is a diagrammatic illustration of cooling at high speed. s

The two-cycle engine I shown in the drawings is mounted on the drive shaft housing ,2 of an outboard motor, not shown in full. The water pump 3, shown diagrammatically in Fig. 4 only, is driven through the drive shaft 4 by engine I and normally receives water from the body ,of water in which the motor is beingoperated. ,-.The

the

. .2 pipe 5 connects pump liver the water thereto for cooling of the engine. y, Pump 3 may be of any type and either of centrifugal or displacement operation with a delivery which usually varies substantially with the speed-of operation of engine I.

' The crankshaft B ofengine I is vertically disposed and the cylinder sleeves Tare arranged in The crankcase of engine I comprises the member 12 and. complementary skirt portions l3 of the cylinder block I4 which define individual crank chambers l5 for each pistons and cylinder 1.

In the operation ofengine I theair-fuel mixture is supplied by the carburetors l6 to the several crank chambers l5 through-valve means, not shown, and is transferred from the crank chambers through the individual passages Hand the. ports l0 into the respective cylinders I when piston 8 uncovers ports [0 with each revolution of crankshaft 6'. The exhaust of each cylinder 1 passes through ports H into the chambers l8.

Cylinder block I4 is comprised of a lightweight alloy which is cast around sleeves 1 and clo'ses the upper ends thereof to form the cylinder domes l9. The several recesses formed in block l4 extend from the crank chambers I5 alongside cylinder sleeves 1 to ports 10 and'comprise the transfer passages I! referred to above.

I The plate 20 secured to the sideof block I4 closes recesseswhich are formed in one side of the block and which overlies cylinders 1. The recesses with plate 20 define the exhaust chambers. l8 referred to above. Chambers I8 open downwardly of block l4 directly into drive shaft housingfll'for delivery and underwater discharge of'the' exhaust from the lowerend, not shown, of, housing 2. T

The'coolant chamber 2| formed in block l4 surrounds the upper ends of sleeves 1 and domes l9 and is closed by the, cover member 22 bolted totheendofblockl l. .Chamber 2| is connected to'pum 3by pipe ,fiwhich is received infthe lowerend of block l4. andopens directly into the l'ower end of chamber 2 l to deliver the water thereto. g .L

The jacket- 23.is; secured .to. block ll over plate 'q'i a eanin -rims ma s i g;

3 and the engine-trade face which with plate 20 provides the coolant chamber 24. The openings 25 in the upper end of plate 20 register with the horizontal passage 26 formed in block M to open into the upper end of chamber 2|. Openings 25 and passage 26 provide communication between chambers 2| and 24 at their upper levels, and for delivery of the water from chamber 21 to chamber 24.

The discharge opening 21 in plate 20 from the lower end of chamber 24 registers with the passage 28 in block I4. Passage 28 extends transversely of the block and opens downwardly directly into housing 2 to provide for the gravity discharge of a certain amount of water from chamber 24, as will be more fully described.

The plate 29 secured to the side of block I4 oppositely of plate closes a recess formed in that side of the block which extends the height of the block and overlies cylinders I and passages IT. The recess with plate 29 defines the coolant chamber. 30.

Thepassage 3| extends across the top of block M from the upper end of chamber 33 and registers with the hole 32 in plate 28 which opens into chamber 24 on the opposite side of the block. Hole 32 and passage 3| thus provide communication between chambers 24 and 30 at their upper levels and for delivery of water coolant from chamber 24 to chamber 30.

The discharge opening 33 at the bottom of block 14 opens from chamber 30 directly into housing 2 and provides for the gravit discharge of water from chamber 36.

Chamber 24 is disposed immediate to exhaust chambers l8 and serves to cool plate l4 and adjacent parts of engine I. The cooling of the exhaust gases passing through chambers i8 is also effected.

In the operation of engine I the heat transfer and protection of other parts of the engine against overheating afiorded by the coolant circulating through chamber 24 is essential to continuous, high speed operation. At low speeds and particularly in cold weather such cooling is of less importance and may be dispensed with entirely.

Chamber 3!} on the opposite side of engine I is disposed immediate to crank chambers IS, the intake side of cylinders I, and extends over passages !1. The water coolant circulating through chamber'39 serves to prevent overheating of the parts on that side of engine i and particularly to prevent heating of the fuel charge enteringthe cylinders from the crank chambers through passages H.

In continuous high speed operation of the engine without adequate cooling, heating of the fuel charge generally lowers the thermal efficiency of the engine and may cause excessive amounts of liquid fuel in the crank chambers 15 and passages H to vaporize and interfere with the operation of the engine.

. However, in operating the engine continuously at low speeds such cooling is unnecessary and undesirable since the parts of the engine referred to may be excessively cooled so that the fuel vapor is condensed in the crank chambers and transfer passages.

According to the invention, chambers 2|, 24 and 30 are arranged in series so that the water is first circulated over the cylinder domes [9 which require the greatest amount of cooling. Thereafter, the water is further heated while circulating through chamber 24 as described. The heated water which is not discharged through opening 21'from chamber 24 is then circulated into passage 3| and through chamber 30.

4 It should be understood that while in practice the actual temperature gradients of the water is not very great, the invention provides for maximum cooling of the cylinders and prevents excessive cooling of the transfer passages.

According further to the invention the sizes of discharge openings 21 and 33 relative to the delivery of pump 3, may be predetermined so that at low speeds, as shown in Fig. 5, the water coolant delivered by pump 3 fills chamber 2|, passes into and through chamber 24 and is discharged through opening 21. Opening 21 should be of such size so that at low engine speeds and low volumetric delivery of pump 3, no water is circulated through chamber 30 and so that at higher engine speeds when cooling of passages I1 is required chamber 24 fills entirely with water and a portion of the water passes into chamber 30.

The size of opening 33 is determined so that the water which enters chamber 36 at intermediate engine speeds, as shown in Fig. 6, passes directly therethrough and by gravity is discharged through opening 33. At high engine speeds chambers and 36 are completely filled when the delivery of pump 3 is greater than the amount which normally is discharged through openings 2? and 33 from chambers 24 and 38, respectively.

The cooling system is particularly adapted for outboard motors which are operated at difierent times in cold water and cold weather or in hot weather, and eliminates the need of thermostatic adjustment means. The cooling system provides, when required, positive pressure circulation of water over the transfer passages of the engine.

Various embodiments of the invention may be employed within the scope of the following claims.

I claim:

1. In an engine or" the class described, a coolant pump operated by the engine adapted to deliver coolant under pressure at varying rates in relation to the speed or operation of the engine, and a coolant chamber connected to said pump to receive coolant therefrom, said chamber having a lower outlet of a specific size in relation to the delivery or" said pump whereby at predetermined higher delivery rates of said pump and greater cooling requirements of the engine the coolant is,

passes immediately by gravity through said cham -oer and from said chamber through said outlet.

2. In an engine of the class described, a substantially positive-displacement pump driven by the engine adapted to deliver coolant under pressure at varying rates in direct relation to the speed of operation of the engine, a first coolant chamber connected to said pump to receive coolant tnerefrorn, and a second coolant chamber communicating at its upper end with the upper end of said first chamber and disposed to receive the coolant therefrom, said chambers. having lower outlets of specific sizes in relation to the delivery of said pump whereby at predetermined higher delivery rates and greater cooling requirements of the engine the coolant delivered to said first chamber in excess of the gravity discharge through the lower outlet of said first chamber is circulated through said second chamber.

3. The invention as defined in claim 1 and ems bodied in a two-cycle engine having a transfer bodied in a twocycle engine having an exhaust chamber and a transfer passage and wherein the first coolant chamber is disposed adjacent the exhaust chamber and the second chamber is disposed adjacent the transfer passage.

5. In a crankcase induction two-cycle engine of the type having a crank chamber, a combustion chamber, an exhaust chamber communicating with said combustion chamber to receive exhaust gases therefrom, and a transfer passage from said crankcase and opening into said combustion chamber to deliver successive fuel charges thereto, several wall member defining first, second and third coolant cavities respectively adjacent said combustion chamber, said exhaust chamber and said transfer passage, and coolant delivery means disposed to circulate coolant through said first, second and third chambers under pressure in that order.

6. In a crankcase induction two-cycle engine of the type having a crank chamber, a combustion chamber, an exhaust chamber communicating with said combustion chamber to receive exhaust gases therefrom, and a transfer passage from said crankcase and opening into said combustion chamber to deliver successive fuel charges thereto, several wall members defining first, second and third coolant cavities respectively adjacent said combustion chamber, said exhaust chamber and said transfer passage, coolant delivery means disposed to circulate coolant through said first, second and third chambers under pressure in that order, gravity outlets for said second and third chambers respectively of specific sizes in relation to the rate of said delivery means, and means for varying the delivery of said means whereby the circulation of water through said third chamber may be entirely dispensed with and the water level within said second chamber may be controlled.

7. In an internal combustion engine, a cylinder block having wall members defining first, second and third chambers adapted to receive a coolant for cooling separate portions of the block, said first and second chambers and said second and third chambers communicating with each other at their upper levels, variable delivery means disposed to introduce coolant to said first chamber under pressure, and gravity outlets for said second and third chambers respectively of specific sizes in relation to the variable rate of said delivery means whereby the circulation of coolant through said third chamber may be entirely withheld and the water level within said second chamber controlled.

8. In an engine of the class described, a pump delivering coolant under pressure at a rate varying generally directly with the speed of engine operation, a first coolant chamber connected to receive coolant from said pump under pressure for circulation and having a restricted outlet limiting the flow of coolant therethrough, and a second chamber having limited communication with said first chamber and a restricted lower outlet, said second chamber receiving coolant from said first chamber at a rate varying with the delivery of said pump and the effective re striction of the outlet of said first chamber, the lower outlet of said second chamber being of a size allowing free flow of coolant through said second chamber during the lower range of pump delivery and engine operation and effecting filling of and restricted fiow of coolant through said second chamber during the higher range of pump delivery and engine operation.

9. The invention as defined in claim 8 and embodied in a two-cycle engine having an exhaust chamber and a transfer passage and wherein the first coolant chamber is disposed adjacent the exhaust chamber and the second chamber is disposed adjacent the transfer .passage.

ELMER C. KIEKHAEFER.

References Cited in the file Of this patent UNITED STATES PATENTS Number Name Date 1,079,440 Rathbun Nov. 25, 1913 1,330,436 Fekete Feb. 10, 1920 1,434,348 Bull Oct. 31, 1922 1,754,689 MacPherson Apr. 15, 1930 1,793,713 Morrill Feb. 24, 1931 1,819,744 Dunkelmann Aug. 18, 1931 1,840,083 Carpentier Jan. 5, 1932 1,848,987 Anibal Mar. 8, 1932 

